Recently, demands for high resolution and high quality images, such as high definition (HD) and ultra high definition (UHD) images, have increased in various application fields. As image data is improved to have high definition and high quality, a data amount relatively increases in comparison to existing image data. Therefore, transmission and storage costs increase when the image data is transmitted through media such as existing wireless or wired broadband lines and is stored in an existing storage medium. In order to address these limitations occurring in accordance with image data having a high resolution and high quality, image compression techniques of high efficiency may be used.
As an image compression technique, there are various techniques such as an inter prediction technique for predicting pixel values included in a current picture from a previous or a subsequent picture, an intra prediction technique for predicting pixel values included in a current picture by using pixel information within the current picture, and an entropy coding technique for allocating a short code to a value having a high occurrence frequency and allocating a long code to a value having a low occurrence frequency. The image data may be effectively compressed to be transmitted or stored by using such an image compression technique.
Furthermore, together with an increase in demand for a high-resolution image, a demand for stereographic image content also increases as a new image service. A video compression technique for effectively providing stereographic image content with high resolution and ultra-high resolution images is being discussed.